Valves are used in myriad systems to control the flow of fluid to and from one or more systems or components. In many systems, these valves are operated using a remotely controlled valve actuator. Such actuators include a torque source that is used to move the valve between its open and closed positions. The torque source may be, for example, a hydraulic actuator, a pneumatic actuator, or an electrical actuator, such as solenoids, and motors.
Many valve actuators are an agglomeration of several components and/or subassemblies that are interconnected and incorporated into the final valve assembly. Although these valve actuators are safe and reliable, each presents certain drawbacks. For example, a valve actuator constructed of numerous individual components and/or subassemblies may increase overall weight, size, and cost of the valve to which the actuator is coupled. In addition, the relatively large number of parts may, among other things, adversely impact the overall reliability and performance of the valve actuator. Moreover, each valve component also takes up a certain amount of scarce interior space for both mounting and connection of and electrical and/or pneumatic interface. In addition, the integrity of some subassembly designs may deteriorate more rapidly in high vibration environment, resulting in increased maintenance costs. One or more of these factors can adversely affect aircraft initial and lifetime costs, as well as aircraft down time.
Hence, there is a need for a valve actuator that has one or more of the following benefits: a fail operate fail safe design; reduced overall system and aircraft weight; improved integrity; a reduced system space envelope; and, simplified system maintenance, without adversely affecting aircraft lifecycle costs. The present invention addresses one or more of these needs.